Calamansi Cloud Cake Recipe

Calamansi is a citrus fruit commonly found in the Philippines. My sister and brother in law are headed there to visit relatives this month, so we're trying a few recipes. Calamansi can be found in California and Florida, but it is not common. You can substitute meyer lemon, lime, or even tangerine juice as a substitute. http://en.wikipedia.org/wiki/Calamondin